• 드라이브 ㆍ 컨트롤
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• 제19권4호
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• pp.36-45
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• 2022

The aim of this study was to verify an E-driving system of a 44 kW-class electric tractor using agricultural workload data. Workload data were acquired during field test (plow tillage, rotary tillage, loader operation, field driving, asphalt driving) using a conventional tractor with a load measurement system. These workload data were converted to data of a 44 kW-class tractor based on the load factor of the engine. These data were used to verify the design of the E-driving system of an electric tractor. High-load operations such as plow tillage, rotary tillage, and loader operation could be performed at stage L and stage M. High-speed operation (asphalt driving) could be effectively performed at stage H using a rated rotational speed of the motor. As a result, the E-driving system of the electric tractor was possible to perform all major agricultural operations according to gear stages of range shift. Based on results of this research, we plan to develop an electric tractor equipped with an E-driving system and conduct research on actual vehicle verification in the future.

• 한국항공우주학회지
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• 제49권6호
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• pp.473-480
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• 2021

소형 무인비행체 드론의 비행제어기(Flight Controller) 소프트웨어로 널리 사용되고 있는 오픈소스(Open Source)에 대한 정적분석(Static Analysis)을 통해 소프트웨어 품질의 문제점을 분석하고 개선 방안을 제시한다. 소프트웨어 품질 기준으로는 국제적으로 널리 적용되고 있는 MISRA 코딩 규칙을 선정하였으며, 정적분석 도구는 국제 도구인증(Tool Certification)을 받아 항공분야 뿐만 아니라 안전성(Safety)이 요구되는 자동차, 철도, 원자력, 의료 등 모든 산업에서 활용되고 있는 LDRA Tool을 사용하였다. 오픈소스 모듈의 구조, 사용 데이터 분석, 코딩 규칙 준수, 품질 지표(복잡도 및 시험성) 등 소프트웨어의 품질 전반에서 안전성을 위협하는 문제점들을 발견하였으며, 이에 대한 개선 방안을 제시하였다.

• 한국방재안전학회논문집
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• 제16권1호
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• pp.71-80
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• 2023

연료전지는 저탄소 발전원으로 주유소 내 연료전지를 설치 시 분산에너지와 전기차 충전인프라를 확충할 수 있다. 주유소 내 연료전지 설치 시 안전성 확보를 위하여 국‧내외 주유소 및 연료전지의 사고데이터를 기반으로 사고시나리오를 도출하고 사고피해예측을 위한 정량적 위험성평가를 실시하였다. 최악의 사고시나리오가 아닌 현실적으로 발생 가능한 화재 및 폭발사고의 피해범위를 산출하고, 피해영향을 분석한 결과 주유기로부터 9.0 m, 주유 중 차량으로부터 15.5 m, 통기관으로부터 4.1 m, 연료전지의 정압기 등 가스조정장치로부터 1.1 m 이상 이격 시 사고로 인한 심각한 피해 위험을 낮출 수 있는 것으로 나타났다. 이러한 연구 결과는 주유소 내 연료전지 배치 및 사고피해를 경감할 수 있는 안전대책 수립에 활용할 수 있을 것으로 기대된다.

• 한국터널지하공간학회 논문집
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• 제25권3호
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• pp.245-259
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• 2023

본 논문의 목적은 국내외 터널 스캐닝 시스템들을 분석하여 비접촉 이동식 상태점검 장비 개발에 대한 시사점을 도출하기 위한 것이다. 국내외 터널 스캐닝 시스템은 레이저 스캔과 이미지 스캔의 두 가지 기술로 개발되고 있다. 레이저 스캐닝 장비는 포인트 클라우드로부터 터널 라이닝의 기하하적 특성을 재현하는데 장점이 있다. 이미지 스캐닝 장비는 컴퓨터 비전을 활용하여 터널 라이닝 표면의 미세한 균열, 누수 등 손상 검출이 용이하다. 터널 라이닝의 손상 검출을 위해서는 이미지 스캐닝 장비가 더 적합할 것으로 분석되었다. 향후 개발 예정인 카메라 기반의 터널 스캐닝 시스템은 조명, 저장장치, 전원 공급 장치 및 차량 주행 속도 동기화 제어 장치로 구성되어야 할 것이다.

• 한국안전학회지
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• 제38권4호
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• pp.8-14
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• 2023

This study presents the characteristics of short circuits (SCs) caused by excessive currents in high-voltage cables used in electric vehicles and emphasizes the need to calculate the cross-sectional areas of these cables according to the SC current. Three direct current power supplies were connected in parallel to test the SC characteristics caused by excessive currents, and a timer and a magnetic contactor were used to deliver the conduction time and SC current. A circular infrared-radiation heater was used to test the temperature-dependent SC characteristics, a thermocouple was used to measure the temperature, and a shunt resistor was used to measure the current. As the SC current increased, the fusing time of the cable decreased. Additionally, a high-voltage cable (with an area of 16 mm² ) used in electric vehicles fused when a current (approximately equal to 55 times the allowable current) flowed for 0.2 s (operating time of the protective device). When the SC current is 10 kA, the cable may fuse during the operating time of the protective device, thus creating a fire hazard. In electric vehicles, the size of the SC current increases in proportion to the capacity of the battery. Thus, the cross-sectional areas of the cables used should be calculated accordingly, and cable operations should be properly coordinated with the surrounding protective devices.

• 한국포장학회지
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• 제29권2호
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• pp.129-138
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• 2023

The proportion of agricultural products handled through the Agricultural Products Processing Center (APC) is also steadily increasing every year, and in the case of Seongju Korean melon, a total of 10 APCs of Nonghyup and farming association corporations are in operation, and the distribution ratio is about 60% based on total production. In this study, Seongju Korean melon was selected as a target to analyze the environment load during carrying (production farm ~ APC) in the production area and the transport environment load during distribution of domestic fruits, and to analyze the environmental load for handling at APC. The vertical average vibration intensity (overall G_rms of 1~250 Hz) of truck transport measured at three transport routes from Seongju Korean melon producer ~ APC, Seongju ~ Seoul and Seongju ~ Jeju was about three times larger than that in the lateral direction and 4.5 times larger than that in the longitudinal direction, respectively. The frequency of occurrence of high-amplitude events (G) in the vertical direction compared to the measuring time was deeply related to pavement conditions in the order of unpaved farm-roads, concretepaved farm-roads, and asphalt-paved main-roads, but overall G_rms for the entire frequency band is believed to have a greater impact on vehicle traveling speed than road conditions. On the other hand, the difference in the size and direction of the vibration intensity measured by the forklift truck's main-body and the attachment (fork carrier) during handling at Seongju Korean melon APC was clear, and the vibration intensity of the forklift truck's main-body was largely affected by the stiffness of the fork and the mast according to the handling weight. Based on the field-data of the transport environment during domestic distribution measured through this study, it is believed that it is possible to develop a lab-based simulation protocol for appropriate packaging design.

• 한국정밀공학회지
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• 제13권9호
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• pp.114-129
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• 1996

This paper describes the whole development phase for the underwater vehicle actuating system with high hydroload torque disturbance. This includes requirement analysis, system modeling, control algorithm design, real time implementation, test and performance evaluations. As for driving control algorithms, fuzzy logic, variable structure and PD(Proportional-Differential) algorithm were designed and implemented on board controller using a single chip microprocessor. Intel 8797. And test and performance evaluation is carried out both single test and wystem integration test. We could confirm the basic performance of actuating system through the single test and gereral developing work of any actuating systems was finished with a single performance test of actuating system without system integration test. But, we suggested that system integration test be needed. System integration test is carried out using G/C HILS(Guidance and Control Hardware-In-the -Loop Simulation) which is constituted flight motion simulator, load simulator, real time host computer and the related subsystems such as inertial navigation system, power supply system and Guidance and Control Computer etc.. The most important practical contribution of this paper is that full system characteristics such as minimal control effort, enhancement of guidance and autopilot performance by the actuating system using G/C HILS technique are investigated. Through full running G/C HILS, in spite of the passing to single tests, some control algorithm resulted in failure as to stability of full system and system time frame.

• 영어영문학
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• 제56권2호
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• pp.329-356
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• 2010

Coleridge's fame as a poet rests on the achievement of the mystery poems, "The Anceint Mariner," "Kubla Khan," and "Christabel." Coleridge's achievement in "Christabel" goes far beyond what previous critics have imagined. Coleridge is one of a handful of great writers who are included as representatives of androgyny. Throughout his life, Coleridge was accustomed to point out feminine qualities within himself. "Christabel" exemplifies the kind of writing contemporary feminist theories call l'écriture féminine. L'écriture féminine is not necessarily the creation of women but may rather be the works of those who refuse to identify with the father and the laws of paternal discourse. "Christabel" becomes Coleridge's most daring symbolic story. "Christabel" appears in its full significance as a vehicle for some profound insights into the dynamics of relationships between men and women, fathers and daughters. Through her deformity, Geraldine is actually the casualty of her father's hatred of women, and is the embodiment of all its anti-virtual aspects. The poem shows no bitterness against women, only compassion and remorse. Coleridge is sympathetically presenting Christabel's suffering as a woman at the hands of an overmastering man. Also, "Christabel" demonstrates woman power as well. In fact, the one person whose tales have any real effect within this narrative is the ambiguous Geraldine. Geraldine excels at story-telling, at making words act for her. Perhaps, despite the appearance of the surface, in which men hold all the cards, it is in fact women, or the feminine, so necessary to procreation and creativity, who hold sway here. This apparent dominion of the feminine derives at least partly from Coleridge's use of the conventions of that feminine genre, the Gothic romance. L'écriture féminine is a concept defined by its divergence from a dominant cultural norm. One may speculate that the fragmentary state of "Christabel" and "Kubla Khan" is in fact congruent with this mode of writing. If these poems imply a theoretical écriture féminine, they are by definition "incomplete," for completeness is a standard of patriarchal language and culture. More perplexing even than the other "mystery poems," "Christabel" is the true fragment of the three.

• 한국ITS학회 논문지
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• 제22권5호
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• pp.43-52
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• 2023

옐로카펫 보급된 이후 어린이 교통사고는 감소세이나 아직 옐로카펫 설치와 교통사고간의 인과관계에 대한 설명력은 부족한 상황이다. 기존의 실차조사연구에서 상황 구현의 어려움이나 위험성 등의 이유로 수행하지 못한 다양한 상황을 VR시뮬레이션 실험을 활용하여 옐로카펫 효과를 더욱 심도있게 분석하였다. 실제 옐로카펫이 설치되어있는 대상지를 선정하고, 가상환경으로 구현한 후 시선측정장비를 착용하고 시뮬레이터에 탑승하도록 하였다. 옐로카펫 설치 전·후의 시각/주행행태를 비교하였고, 통계적 검증을 위해 t-test 분석을 수행, 모두 통계적으로 유의한 수준인 것으로 나타났다.

• 한국포장학회지
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• 제29권3호
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• pp.203-209
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• 2023

The increasing saturation challenges in storage facilities for Low- and Intermediate-Level Radioactive Waste call for a more efficient storage approach. Consequently, we have developed a square-structured container that features a storage capacity approximately 20% greater than that of conventional drum-type containers. Considering the need to contain various radioactive wastes from nuclear power usage securely until they no longer pose a threat to human health or the environment, this study focuses on evaluating the sealing efficacy of the newly designed rectangular container using finite element analysis. Since radioactive waste containers typically do not experience external forces except under special circumstances, our analysis simulated the impact of an external force, assuming a fall scenario. After fastening the bolts, we examined the vertical stress distribution on the container by applying the calculated external force. The analysis confirms the container's stable seal.